Fountain pen



Sept. 19, 1950 F. E. BARTELL FOUNTAIN PEN 2 Sheets-Sheet 1 Filed March 3, 1947 My M O l 0 I O i I- OllllOOlllllli INVENTOR. Floyd 554v tell A T TO RNEYS Patented Sept. 19, 1950 FOUNTAIN PEN Floyd E. Bartell, Ann Arbor, Mich., assignor to The Parker Pen Company, Janesville, Wis., a corporation of Wisconsin Application March 3, 1947, Serial No. 732,032

22 Claims. 1

My invention relates generally to fountain pens and it has to do particularly with fountain pens of the type having an ink reservoir adapted to be filled by capillary action and which retains the ink therein by capillary action, subject to discharge to a writing surface under control of capillary feed means.

An object of my invention is to provide an improved fountain pen of the foregoing character.

Another object is to provide a capillary filler element having improved means for maintaining thewall members which define the capillary ink space in pre-determined spaced relation positively throughout their length and breadth and without material obstruction of the capillary space defined therebetween.

Still another object is to provide a capillary filler element wherein the capillary ink storage space is defined by thin sheet material of convolute form, the several convolutions of which are positively self-spacing throughout substantially the entire extent of the filler element.

A further object is to provide a filler element of high effective ink capacity which is fully ventilated and which fills rapidly and completely retains the ink against leakage under conditions of varying temperatures and pressure, and writes out freely and completely Without flooding or starving.

Still a further object is to provide a capillary fountain pen having improved ventin means for equalizin the fluid pressure in all portions of the pen rapidly and completely, thereby main taining balanced fluid pressure in the pen substantially at all times, even when the pen is subjected to varying conditions of temperature and pressure.

. Another object is to provide a capillary filler element having a substantially continuous capillary space of convolute form wherein adjacent oonvolutions are interconnected at a plurality of portions thereof to permit relatively free flow of fluid between adjacent convolutions.

Another object is to provide a capillary fountain pen having improved means for feeding ink from the ink reservoir to the Writing element.

A further object is to provide a capillary filler element havin an improved feed integral therewith for feeding ink from the ink storage space Within the capillary filler element.

A further object is to provide a capillary filler fountain pen having improved means for maintaining the capillary filler element in position in ink feeding relation to feed means connectin the filler element to the writing element.

Still another object is to provide a capillary filler fountain pen wherein a capillary filler element formed from thin sheet material is firmly positioned in the reservoir in such manner that it is not subjected to damaging stresses thereon and the effective volume of the ink reservoir is not substantially decreased.

A further object is to provide a fountain pen having an improved capillary filler element which is simple and easy to manufacture and assemble in a pen, which has a high effective ink capacity, and which will not deteriorate or decrease in efficiency over a long period of use.

Other objects are to provide a capillary filler fountain pen having a capillary system formed with a minimum of sharp corners and sudden changes in cross-sectional area; to provide a capillary filler fountain pen having a capillary ink space of relatively large total cross section and which is at the same time capable of rapid filling; to provide a capillary filler fountain pen having a large number of small capillary passages conmeeting the ink storage space with an ink feed connected to the writing element; to provide a capillary filler element which may be readily assembled in and removed from a fountain pen body; to provide a capillary filler element which may be formed from a single sheet of material and in which the several portions of the sheet definin a capillary ink storage space are positively spaced apart substantially throughout their length and breadth; to provide an improved capillary filler element which lends itself readily to economical quantity production; and to provide a capillary filler element which is self-venting and requires no separate air vent leading from the several portions of the filler element.

Other objects and advantages of the invention will appear from the following description taken in connection with the appended drawings wherein:

Figure 1 is a longitudinal view of a fountain pen embodying my invention;

Fig, 2 is a transverse, sectional view taken along line 2--2 of Fig. 1;

Fig. 3 is a transverse sectional view taken along line 3-3 of Fig. 1;

Fig. 4 is a transverse, sectional view taken along line 44 of Fig. 1;

Fig. 5 is a perspective view of the bushing or sleeve for mounting the nib or feed bar;

Fig. 6 is a side elevational view of the capillary filler element of the pen shown in Fig. 1;

Fig. 7 is a rear-end View of the capillary filler. element shown in Fig. 6;

Fig. 8 is an enlarged, fragmentary sectional view taken approximately along line 8-8 of Fig. 6;

Fig. 9 is a plan view of the sheet from which the filler element is formed, after completion of the formation of the projections and fringe but prior to spiral wrapping or rolling of the sheet.

Fig. 10 is "a side elevational'vie'w of another form of capillary filler element embodying my invention;

Fig. 11 is a rear-end view of the capillary fille'r element of Fig. 10 i Fig. 12 is an enlarged fragmentary sectional view taken approximately Fig. 10;

Fig. 13 is a fragmentary view partially in lon 4 respect to the other members with which it cooperates. A plurality of slots 26 (Figs. 1, 3 and 5) extend through the flange 25 to provide ink passages for a purpose hereinafter described. A feed bar 30 is associated with the nib I2 for feeding ink thereto and is frictionally secured snugly in the bore 24 of the bushing 20. The feed bar 30 extends forwardly in the nib I3 and is formed with a diameter slightly less than the nib body I4 thereby providing a generally arcuate capillary space 3! between the nib body I4 and the feed bar 3!].

The feed bar 30 is provided with V a reduced forward extension 32, the forward end gitudinal cross section showing a modified form of feed connection between the filler element and the writing element;

Fig. 14 is a transverse sectional view taken along-line M=M of Fig. 13; and

Fig, 1-5 is a somewhat diagrammaticen'd view of anotherembodiment of a fill-er-and reservoir element.

The present invention is illustrated in connection with a fountain'pen of the desk type, but it is to be understood that the invention is'equally well adapted for embodiment in a fountain pen of the pocket type, or the dual purpose type wherein the pen is adapted to receive either a short tail piece for use as a pocket pen or an elongated tail piece for use as a desk pen.

Referring now particularly to Fig. 1 of the drawings, there is shown forillustrative purposes a fountain pen comprising a body or casing I formed of suitable material such as a plastie and which, for convenience in manufacture and assembly, is formedas a plurality of separate members or sections. The body I includes a barrel or forward section .2, a rear section 3 connected thereto as by a threaded joint 4, and an end or tail piece 5 attached to the rear section 3 as bya threaded joint 6. Ihe forward section 2 is formed with an axially extending bore which defines an ink reservoir chamber, I and which is adapted to receive a capillary filler and-reservoir element II hereinafter described more in detail. An opening 12 extends axially vfrom the reservoir chamber I0 through the forward or Writing end of theforward section 2 and is adapted to receive the writing element and feed hereinafter described.

A writing element of suitable form is carried at the forward or writing end of the body I and is connected b suitable ink feed means to an ink-storage reservoir hereinafter described in detail. The writing element may comprise a nib I3 disposed in the opening I2 with its writing tip projecting beyond the forward end of the bod I and exposed for writing. The nib I3 may be of any suitable construction and preferably includes a general cylindrical body portion is having a slot I in its under side, and a tapered arcuate forward portion I6 provided with the usual nib slit I7 terminating inwardly in a pierce I8. The nib -I3 preferably is mounted by a bushing or sleeve secured by external threads 2| in a counterbore 22 formed at the inner end of the opening I2.

The bushing 20 (Fig. 5) has a bore 23 and a counterbore 24 which provide an external flange 25 adapted to serve as an abutment for the rear end of the nib i3 when the latter is inserted in the bushing 20. The bushing 20 snugly receives the nib body I4 and servestoposition it with of which engages-and supports the forward end of the nib I-2 in the usual manner.

The arcuat'e capillary space 3i is connected in ink feeding relation to the reservoir by an ink feed slot 33 formed in the upper surface of the feed bar which slot extends from the rear end of the feed bar 30 to forwardly of the nib pierce 1B, in alignment with the nib slit '1'! and nib pierce I 8. Additional feed slots 34 preferably are providedin the sides and-bottom of the feed bar 39 and-extend from-the rear end of the feed bar at least to the arcuate capillary space 3| to connect the latter with the ink reservoir.

The opening I2 in the forward section 2 preferably is relieved in its upper wall, above the nib I3, and defines with the nib an'arcuate-capillary ink space 35 (Figs. 1 and 2) extending-above the nib slit I1 and pierce I8. Thus, whenever'ink is contained in the pen, ink is always drawn into the space 35 by capillary action and maintains this space filled and thus the adjacent nibslit I1 andzpierce I8 are maintained in wetted condition at all times and the pen, therefore, is always-in condition for instant writing.

The present inventione'mploys a capillary fillerand r'eserv'oir element (also referred to herein as a filler element) for defining an ink reservoir which fills by capillary action and retains the ink by capillary action in such manner that the pen will not leak even when subjected to conditions which might otherwise cause leakage, as, for example, changes in temperature or pressure, but which reservoir permits the ink to be withdrawn from the pen uniformly under capillary control when the penis used in writing. According to the present invention the capillary filler-and-reservoir element I I (illustrated somewhat diagrammatically in the drawings for a clearer understanding thereof) is formed from a thin-walled'sheet of material 36 (Fig. 9) wrapped or rolled into spiral form (Figs. 6 and 7). Conse'cutive convolutions of the spirally wrapped sheet are spaced apart preferably equal distances to provide a continuous space 31 of generally spiral cross sectionv and uniform capillary walltoewall vwidth extending longitudinally substantiallythroughoutthe length of the filler element.

The capillary filler element II preferably is formed by spirally wrapping or rolling upon itself a thin sheet of suitable material such as metal or plastic which has such surface characteristics that it is suitably wettable by inks of the type customarily used in fountain pens and insures the desired capillary action for controlling the ink as hereinafter explained. The material forming the sheet 36 has suflicient rigidity to maintain its shape and position when rolled but is sufficiently flexible .to permit it to be rolled readily. The sheet :material also is suitably resistant to the ink used-so that it is not adversely affected by the ink and doesnot deteriorateupon continual contact of the ink. Excellent. results have-beienobtained by using thin sheet material or foil formed from silver, although other materials may be employed as, for example, other metals, such as gold, magnesium alloys (one example of which is an alloy consisting of 9% aluminum, 0.1% manganese, 2% zinc and the remainder magnesium), also aluminum alloys (one example of which is an alloy consisting of 5.2% magnesium, 0.1% manganese, 0.1% chromium and the remainder aluminum), and plastics such as ethyl cellulose, Vinylite and others. The material from which the filler element is formed may be treated suitably in a known manner to provide a surface having increased Wettability.

The filler element I I is formed to provide a pen having the maximum practicable effective ink capacity for any over-all external dimensions of filler element, that is, the pen has the ability to draw in during filling and to retain the maximum amount of ink with the maximum write-out and refill characteristics. Accordingly, the pen is formed with as great as possible a capillarity, limited, however, to a capillarity not greater than that which will permit the ink to be written out of the pen. For any particular material having a particular degree of Wettability, the capillarity of the filler element may be predetermined by suitably dimensioning the width of the capillary space defined between consecutive turns of the sheet. The filler element II preferably is made of such length that the capillary space defined thereby is substantiall filled when the pen is filled by holding it in a vertical position and thus the pen will not be overfilled even if it is filled by holding it an an acute angle with respect to the surface of the body of ink from which the pen is being filled.

The sheet 36 from which the filler element I I is formed is of such dimensions that when rolled into spiral form with the consecutive convolutions spaced at the desired distance, the diameter of the roll is such that the filler element fits snugly in the reservoir chamber ID. The length of the sheet, therefore, is selected to provide a roll of the desired diameter to substantially fill the reservoir chamber II]. The breadth of the sheet is so selected that, when it is rolled into spiral form, the capillary filler element is of such length that the desired ink storage capacity is provided. The capillary space '3'! comprises the principal ink storage space and may, therefore, be considered for all practical purposes as being the ink reservoir space. It will be understood, however, that additional ink storage capacity may be provided, as, for example, by spacing the outer turn of the filler element I I inwardly of the wall of the chamber i sufficiently to provide a capillary space therebetween.

In accordance with the present invention, means are provided for accurately and positively spacing consecutive turns of the capillary filler element I I substantially throughout the length and breadth of the latter to insure that the width of the capillary space 31 is accurately predetermined and maintained without, however, causing any substantial obstruction of the space 31. This is accomplished by providing a plurality of small, spaced or discontinuous spacing elements associated with the convolutions of the filler element. Preferably the spacing elements take the form of spaced projections 38 (Fig. 8) extending from the convolutions of the sheet and abutting adjacent convolutions. The projections 38 may be provided conveniently by displacing the material of the sheet out of the planethereof to form a series of bumps or pimples. While the projections 38 may extend in either or both directions out of the plane of the sheet, yet for convenience in manufacture and assembly, preferably they all extend in one direction, and when the sheet is rolled, all of the projections in a single convolution abut the next adjacent convolution of the roll. While the sheet may be rolled either with the projections facing inwardly or outwardly, preferably, to facilitate assembly of the filler element in the pen body, the sheet is rolled with the projections facing inwardly. The projections 38 are disposed in closely spaced arrangement substantially throughout the length and breadth of the sheet 36 and hence when the sheet is rolled they serve to maintain the several portions of the sheet in positively spaced relation. The sheet 36, when rolled into spiral form, provides a structure which is self-rigid and which may be handled and assembled in the pen body without disturbing the arrangement or spacing of the several convolutions thereof. Since the projections are of small diameter and are spaced both longitudinally and laterally of the sheet, the capillary space 37 is not materially obstructed and ink or air may flow freely therethrough." Any suitable arrangement of the projections may be employed but preferably they are disposed in equally spaced rows and columns.

The several convolutions of the capillary space 31 are connected along their longitudinal line of juncture as above described. However, in order to provide additional intercommunication between the several convolutions to permit substantially free flow of air or ink between the several convolutions, and to insure full pressure equalization of the fluid contents of the pen, additional communication between the adjacent convolutions of the space 31 is provided. This additional intercommunication is provided by forming a plurality of spaced openings 39 (Fig. 8) in the turns or convolutions of the sheet 36, thereby providing what I term cross-venting. The openings 39 preferably are formed when the sheet is in fiat condition and preferably are arranged in uniform rows and columns. However, if desired, other arrangements of openings may be employed. The openings 39 may be provided in the projections themselves, as illustrated in Figs. 6 to 8, or intermediate the projections, as illustrated in Figs. 10 to 12 and described hereinafter. The projections 38 and perforations 39 may be formed simultaneously in a convenient manner by punching the sheet 36 with a punch or a plurality of punch elements of suitable diameter which both raises the projections and perforates the sheet. The punching operation may be so performed as to rupture the sheet at each of projections 33 and thereby provide one or more side openings Ml in the side walls of the projections 38, Thus, even though each projection 38 at its uppermost portion may abut snugly against the adjacent convolution of the sheet 36, yet the side openings 40 provide a plurality of passages through the sheet and connecting the adjacent convolutions of the capillary space 31.

It will be understood that the capillary filler element may be formed from an unperforated sheet having bumps or projections formed therein in a manner similarly to the sheet 6| (Figs. 10 to 12) but preferably the filler element is formed from a sheet which is perforated to provide crossventing as explained thereinabove.

The capillary filler element II, after completion, is inserted in reservoir chamber I0 (Fig. 1)

sagtaagect 7 with its forward endin abutmentwith the -for- Ward end wall of the reservoir and' with the rear 'or'inner faces'o'f 'th'e mounting bushing 20 and feed bar 30, respectively, ther'eby placing -the capillary space I 3-! in direct I ink feeding-connection with the slots 26 in the bushing and the feed slots 33 and- 34 in the feed bar"3'll. To insure that ink is drawn from'the r capillary space- 3 into the feed slots '33 anii 3'4, feed means-"of greater capillarity than the: capillary space 3-! is "provided adjacent the rearward end- 'of the feed "bar 30. Such means -preferably comprises -a fringe-like element which may be iormed integ-rally with thefiller element by providing "what Iterm a feathered edge on the sheet 36. The

f-eathered edgeis provided preferablyby forming a plurality :of short closely spac'ed slits :42 in-a margin of the --sheet 36 which slits 'define a plu- :rality of:"tongues or-"eathers 4-3. W-hen theishe'et is thus slitiand th'entrolled into spiral form- -the i severalslits 42between adjacent feathers 43 become sufiiciently open to provid'e 'a plurality-of narrow capillar-y passages which, when the fringed end tl otthe filler elemeht His caused to abutthe "end walls "of the bushing-20 and" feed 1 bar 3 0, connect the capillary space- 31 with the feed slots-33 :and34 and the slots 26in the-bushing 20.

The capillary filler 1 element =-H .is 1 positioned positively in -the reservoir chamber l so that the forward end of the former remains --in'--' abutment withtthe forward. end walhof the reservoir chamber l0-and withthe rear-ends of the bush- -ing-120.and feed bar30. While the'eapillaryfiller element 1' lsm'aybema intained against rearward displacement solely by abutment between the forwardviendtzli D iofthe': rear: section:- 3- and the wearaward end :of the'x'fillereelement -l l, '-preferably Iwcprovide means for firmlyzmaintaining thefiller element- [1 Lin zposition'oin:suchcmannerzas to- :pre-

vent it from being ziiamagedaby vlongitudinal ,stresseswthereon. Suclrpositioninglmeans zpre'ferably includes an :annular.'ring;:or iwashereill formed of ar-ubber :or :iothert suitable aresilien-t,

yieldablematerial, whichisuinterposed between the .for'ward endi 50 ofithezrear; section 13; and zthe rearwarduend of: thefillerielement. Ll. .W'henfithe filler element H is iniapositiondn thegpencbo'dy and the vxbody sections; ;2 land; 3i are :assembled; the ring 5| :exerts-a slight :yieldingipressurei against the filler xelement I Icsufficient .to-imaintainritrin its desiredyposition:during alliconditions Of'iOlllS- .tomary use. The ring .'5lv;mayibe;proyided with notches orslots v52am its forwardiedgeutoiipermit air toypass fromwthe outer turnscof.:.the:capillary space 31 g to 'the interior :of the1ringr5l1sfor venting the-a air, :as hereinafter 1 explained.

The reservoir chamber I -U is. vented =to 1atmosphere in order Ito. maintain the fluid pressure in the reservoir equal to atmospheric pressure and thus prevent the establishmenttof; a:.press.ure differential betweeni-the interior. and *exterior :of

the pen suchas mightioccur, ln'thB IabSenCBIJOf such venting, upon a r-decrease in atmospheric pressure, or uponian-increase in the airepressure Within the pen,:las, .for example, when the -pen is heated by therwarmth of: the hand. .The cross-venting between vthe several eportionsmof the capillary spaceprovides relativelyvcomplete :and substantially instantaneous equalization .of pressure throughout all, portions "of. the interior of theipen. (The prevention :of a pressure differential between the (interior and-exterior:iofslthe pen and -the several tportionsz'of .thEZintBIiOI'flnsures '7 that the feed Mather-pen will-.not; floodior starve durin periods of writing and that :the pen will not leak during periods :of non writing.

In the embodiment of my invention illustrated in the drawings (Fig. l) the pen-body is provided with -a venting system connecting the reservoir chamber .10 with the exterior of the pen, which system includes aplassage 55 in the rear body section 3, a passage 56 in :the tail piece ;5, :andza vent outlet 51 at the joint between the rear :sec-

tion 3 and tail piece .5. "Thus-when the tail piece 5 is unscrewed slightly, the outlet 51 provides free communication between the vent passagetfi and the exterior of the :pen. vOn=.the.-o.ther hand,

when the tail piece is screwedion tightly theont- .let port'5l maybe c'ompletelywlosed, but ipreferably the joint is not'made air-tight andaper- .mitsair to leak there-pastzatnallctimes southat 'the interior of the pen is-alwayssufficiently-vented :to maintain the pressure :there'msubstantially :at

atmospheric :p ressure.

The pen isflfilledby merely-.dippingthefforward 'or'writing endiinto a. supply of ink, the tail piece 5 preferably having been :unscrewed slightly to provide free venting for theinterior of the pen. .Ink is'drawn into the peni-bylcapillary actionand, by reason of the interconnection and capillary irelationship'between the several portions of the capillarysystem within the pen, rises tocompletely fill thecapillary'system. :Ink

is drawn into :the .pen, through the aartcuate capillaryspace 31 between the-nib l3 and the feed bar 30, and thence throrugh'the feed'slots 33 -andi3.4

and into the forward end of the :capillary space 31 ;and.also into thepassages :42 ;defined-by;the fringe 14!. .Ink :also may be drawn 7: into the nib slit I1 and thence :into the'zarcuate, space ,3l.

In addition, ink may be drawn intothexpen through thespace between :the nib l2 and the body I iandthence through :the nib slit ligand nib pierce l8 and into ,the:calpillaryspacez3'l and also through theslots :26 in, the. bushing andiinto the capillary spacegtl. Where the pen is.1inserted to a suificient depth in the body ,of

ink,.ink' maybe drawndirectly into the slots26 and :thence :into the capillary, space 131. The slots26 provide filling passages of relativelylarge total cross section which permit-raDid-filling ,of the-pen. Ink :is fdrawn; from the [51013826,111 the bushing 20 and, slots 33-,and 34 in the feed bar .into' the capillary feed passages 142- defined by the fringe elements' ltand also into the portion of the capillary space 3? defined by the consecutive turns of the. filler element! l. Ink finds-its vway intoall portions of the oapillaryspace-S],

inasmuch as .all of the convolutions thereof are interconnected, both along their longitudinal lines of juncture and-also by virtue ofthe crossventing between consecutive turns which ispro- .videdaby the aopeningsz-ztl. "Ink gtlrusvrises in; the

capillary space t'l toga height which -de ends *upon the capill-arity of thefil-lerelement, the-lat- .terrbeing so; formed that it preferably; cavusesink toarisesubstantially to the topof, this element .when the pen is held verticallyv in. respect .170? the surtace of the'bodyof ink-.fromz-whioh.the,pen isa'beingfilled.

-. Air *which is .in thecapillary F Space 3:31 when thepfilling operation is, initiated-is forced toutby the incoming ink and finds its Way through, the vent passages and 56 and the :outlet portg- 51.

sAllxofthezseveral turns of thelicapillary; space 31 communicateiwith. the vent; passages '55; andithu :air-passesi freelyput'iof .allz portionsof": the space 231:" at the, reanend:thereofzandihere;:is;::noi like- .lihood of an, airelockzretardingior .1blockingz'rth .tions of the capillary space.

of the nib at all times.

element 1 I may be of capillary width and utilized as ink-storage space. In the event that an air bubble should form in any portion of the capillary space 31, such bubble would tend to rise in the capillary filler element until it passes out of the top of the latter since all of the several turns or convolutions of the space 31 are interconnected. If an air bubble is blocked against rising along a particular portion of the space 31, it will drift into another portion where it can find its way out of the rear end of the filler element II. The cross-venting between adjacent portions of the capillary space 31 provides rapid flow of ink or air between the several portions and equalizes the fluid pressure within the pen rapidly so that any condition which might arise tending to cause air-block either during filling or writing would quickly be eliminated.

In a pen constructed in accordance with the present invention, the construction of the filler element provides substantially complete assurance against air-locking because of the relatively free intercommunication between the several por- While the pen is so constructed that all portions of the capillary space are made to have as nearly equal capillarity as possible yet owing to slight variationsv in dimensions between the various portions of the space 31 which occur in manufacture the capillarity of the several portions of the space 31 will vary even if only to a very small degree. This slight variation will provide, in one portion of the capillary filler element I I, a capillary path having a slightly greater capillarity than in an other portion of the filler element. Thus ink will tend to rise along the path of highest capillarity during filling and air will be expelled along the paths of lesser capillarity so that a condition is created which will tend to break up any air bubbles of such extent as might tend to cause airlocking. In addition, the filler element ll may be provided with a central space 44 of slightly greater transverse dimension than the remainder of the void space, which central space provides a path of lesser capillarity and permits air to be vented therethrough during filling.

In writing, when the writing tip of the pen nib I3 contacts the writing surface, the capillarity established between the tip and the writing surface causes ink to be drawn from the pen.

Ink to replace that which is withdrawn from the point during writing or which evaporates during periods of non-use is drawn from the capillary space 31 through the feed slots 33 and 34 and finds its way into the arcuate space 3| and thence into the nib slit l1. Ink also may be drawn into the space 35 above the nib and thence into the nib slit [1.

The feed connecting the capillary space 31 with the writing tip of the nib I3 is so formed as to insure that ink will be drawn to the writing tip Accordingly, the capillarity of the nib slit I1 is the highest of any portion of the capillary system which extends from the space 31 to the nib slit l1.

Air to replace ink which is withdrawn from the reservoir is drawn into the pen through the several" vent passages in a direction opposite to that through which air is vented when the pen is filled.

The capillary filler element may be formed in various sizes with the several portions'thereof variably dimensioned in accordance with the principle indicated in the foregoing description. In one practical embodiment of a fountain pen employing my invention and wherein the over-all dimensions of the pen were similar to those of a conventional fountain pen, excellent results were obtained by forming the filler element as follows: A sheet of silver foil approximately 0.001" in thickness and approximately 8" in length by approximately 1%" in width was provided with perforated projections 38 arranged in rows and columns approximately apart extending substantially throughout the length and breadth of the sheet (Fig. 8), except along the forward marginal portion thereof. The projections were approximately 0.008"in height and the perforations therethrough were approximately 0.015" in diameter across their outer edges. A feathered edge was provided on the sheet by forming slits 42 extending inwardly from the edge approximately I35" in length and spaced apart approximately longitudinally of the sheet. The sheet thus formed was spirally wrapped into a roll H approximately 0.310" in diameter with each convolution thereof abutting the inwardly extending perforating projections. The feed slots 33 and 34 in the feed bar 30 (Fig. 1) and the capillary space 3| were of less width than the spacing between opposite wall surfaces of the filler element but were wider'than the nib slit I6 and.

generally were approximately 0.003" in width;

invention is n'ot'limited to the foregoing dimensions and the latter may be varied in accord with the principles hereinabove stated without departing from the invention. For example, excellent results have been obtained by forming filler elements from sheets ranging in size from 8" to 15" in length and 1% to 2" in width, in which filler elements the spacing between turns ranged from approximately 0.008" for an 8" sheet to 0.004" for a 15" sheet. Excellent results have been obtained with perforations from 0.01" to 0.04" in diameter although larger perforations may be employed. Excellent results have been obtained by spacing the perforations approximately 1 mm. apart in rows spaced at approximately 3 mm. but the spacing may vary substantially.

Various modifications may be made in the structure of the pen without departing from the scope-of the present invention. For example, instead of forming the projections in the capillary filler element by puncturing the sheet from which the filler element is formed, the projections may be formed without openings as illustrated particularly in Figs. 10 to- 12, inclusive. The projec tions 62 may be formed of generally hemispherical shape thus providing a relatively high degree of strength which strongly resists collapse of the projections even though substantial pressure may be applied to thesheet during the forming or assembling operations. .sirable to provide perforations in the sheet for In this case, if it is de- .chined or 'close fitting parts.

forming the filler element H shownin Fig. 6 .orthe sheet 6| (it) shown in Fig. 10) spirally Wrapped together forming thefiller element instead of from a singlesheet. Such a construction is illustrated in Figwherein the filler-and-reservo'ir element 10 is formed: by a plurality of sheets H. which. preferably are similar to the sheets 36 above described. However,

for simplicity in. manufacture and. assembly I prefer to form the filler element. from a single sheet.

. Inorder to aid in the feed of from the capillary: space within the capillary filler element to the feed slots in the feed bar, and particularly to provideoneor more. feed paths directly'connecting the. outermost turns of the capillary space with; the feed slots, a plurality of transverse. feed passages may be provided adjacent the forward end'of the capillary filler element intersecting the several turns of the capillary space at. its

forward end; Such an embodiment of my) in- .vention is illustrated particularly iii-Figs; Band 14 wherein the forward end wallof the body section 10 defining the reservoir chamber; the rearward end wall of the mounting bushing H. and the rearward end wall of the-feed barr12' are provided with a series of grooves 13- such as may be formed by a knurling operation; Thus,v alarge number of intersecting feed: passages are-provided across the faces of the respective numbers, which feed passages serve to. connect the forward endsv of the'severalportions'of the ca illary filler element and the several feed passagestsuch as the feed slots 14 and 15 in the feed bar-1.2

which lead to the nib slit (not shown).

Various arrangements of projections andperforations in the sheet may be employed in. addition to those shown in Figs. 6' and 10. For example, they may be arranged in spaced rows extending at an angle tothe direction of. wind. of

the sheet. Also they may be spaced. variably instead of uniformly, in the direction of wind.

In the latter case the spacing of the rows'may be graduated so that an' equal or an approximately equal number of rowsv are disposed in each turn by simple hand operations, it. lends itself' readily to quantity production. The assembly of the filler element in the pen body does. notlrequire any special tools or the use of any accurately ma- While it is, of course, desirable that the nib andv feed bar be accurately formed and positioned, on the other hand the capillary filler element itself requires no close-fit with the associated members.

The capillary filler element is so formed that it'provides in a pen of any particular over-all size a maximum of effective ink space, that is, a

maximum volume of ink storage space which will fill by capillary action during filling of the pen, retain the ink during periods of non-writing .and Write out the ink during writing and which will refill and Write out repeatedly. The wall member from which the capillary filler element is formed may be made of very thin metal and thus consumes a relatively small percentage of the total volume of the capillary filler element. On the other hand, by virtue of the novel construction of the capillary filler element, all of the wall portions which define capillary spaces are positively and accurately self-spacing to provide a relatively rigid filler element. and to maintain the several portions of the filler element spaced throughout the assembly of the pen and all ordinaryconditions of use. The self-spacing of the convolutions of the filler element provides a. minimum of obstruction of the capillary space. Moreover the filler element being inherently self-rigid does not require any supporting or mounting means but may be inserted directly in the reservoir chamber of a pen body and may be supported solely by engagement with the end and side walls of the chamber. Where a resilient positioning member is provided as described hereinabove, such member may be of relatively small dimensions and thus does not consume any substantial space within the ink reservoir chamber.

The capillary filler element is so formed as to be self-venting and, therefore, will free itself of any tendency to air-lock either during filling or writing. The cross-venting between the several oonvolutions of the capillary Space insures a high degree of equalization of the fluid pressure in all portions of the pen and thus prevents leakage which might otherwise occur owing to changes in temperature or pressure. Moreover the provision of relatively free intercommunication between the several portions of the capillary space, together with the provision of an ink space of relatively large cross section, permits rapid filling of the pen. The equalization of pressure within the pen and the numerous feed passages connecting the capillary filler element with the writing element insures a uniform and free feed of ink during writing and the pen does not starve or flood.

The capillary filler element is so formed that substantially all of the capillary space is of uniform capillarity and the. capillary connection between the capillary space within the filler element and the writing element has a minimum of sharp corners or sudden changes of cross-sectional area and thus there is a minimum possibility of capillary edge eiiect occurring within the capillary path. Accordingly, the pen has a relatively high write-out capacity and a relatively high effective storage capacity.

I believe that the operation and advantages of my invention will be well appreciated from the foregoing description, and it is to be understood that, while I have shown and described several forms of my invention, other details and arrangements of parts may be resorted to without departing from the spirit and scope of my invention as defined by the claims that follow.

I claim:

1. A fountain pen comprising a body having a reservoir section and a feed section, a writing element at the forward end of said body, feed means in said feed section associated with said writing element, and a capillary filler-and-reservoir element formed of perforated sheet material disposed in said reservoir section and having spaced, opposed wall portions andmeans on said wall portions and abutting opposing wall portions for maintaining the spaced relation thereof whereby said wall portions define therebetween a capillary ink storage space extending longitudinally of said 13' reservoir section and in ink feeding relation with said feed means.

2. A fountain pen comprising a body having a reservoir section and a feed section, a writing element at the forward end of said body, capillary filler-and -reservoir means in said reservoir section including opposed wall portions of nonabsorbent sheet material, means maintaining said wall portions disposed in predetermined spaced relation to define a plurality of capillary ink storage spaces therebetween, said wall portions having spaced openings extending therethrough providing communication between the capillary spaces on opposite sides of said wall portions, and capillary ink feed means in said feed section connecting said ink storage space in ink feeding relation with said writing element.

3. A fountain pen comprising a body having a reservoir section and a feed section, a writing element at the forward end of said body, capillary filler-and-reservoir means in said reservoir section including opposed wall portions of sheet material disposed in said reservoir section, at least certain of said wall portions having projections extending therefrom for abutting and spacing the opposing wall portions, whereby said opposed wall portions define capillary ink storage spaces extending along said reservoir section, and openings in said wall portions providing communication between said capillary spaces on opposite sides of said wall portions, and capillary ink feed means in said feed section connecting said ink storage space in ink feeding relation with said writing element.

4. A fountain pen comprising'a body having a reservoir section and a feed section, a writing element at the forward end of said body, capillary filler-and-reservoir means in said reservoir section and retaining the ink therein by capillary action including a spirally rolled wall member of non-absorbent sheet material, and means on said wall member for spacing consecutive convolutions thereof predetermined distances apart to provide therebetween a continuous capillary ink storage space of spiral cross section extending longitudinally of said reservoir section, and capillary ink feed means in said feed section connecting said storage space in ink feeding relation with said writing elements.

5. A fountain pen comprising a, body having a reservoir section and a feed section, a writing element at the forward end of said body, capillary filler-and-reservoir means in said reservoir section including a spirally rolled wall member having projections extending therefrom and abutting adjacent convolutions of said wall member thereby spacing consecutive convolutions to form a continuous capillary ink storage space of spiral cross section extending longitudinally of said reservoir section, and openings through said wall portions providing communication between the portions of the storage space on opposite sides of said wall portions, and capillary ink feed means in said feed section connecting said storage space in ink feeding relation with said writing element.

6. A fountain pen comprising a body having a reservoir section and a feed section, a writing element at the forward end of said body, feed means in said feed section associated with said writing element, and a capillary filler-and-reservoir element formed from non-absorbent sheet material disposed in said reservoir section and spirally wrapped upon itself, means spacing the convolutions of said sheet material predetermined distances apart to define therebetween a continuous 14 capillary ink space of generally spiral cross section, said sheet material having its forward end portion formed with a plurality of slits providing feed passages of greater capillarity than said capillary space and connected in feeding relation to said feed means.

'7. A fountain pen comprising a body having a reservoir section and a feed section, a writing element at the forward end of said body, a capillary filler-and-reservoir element formed from a member of sheet material of convolute form, and having therein means spacing the convolutions of said sheet whereby they define a capillary ink storage space therebetween, and vent openings extending through said convolutions and providing communication between the portions of said capillary space on opposite sides of said convolutions, and capillary ink feed means in said feed section connecting said ink storage space in ink feeding relation with said writing element.

8. A fountain pen comprising a body having a reservoir section and a feed section, feed means disposed in said feed section, a pen nib associated with said feed means, capillary filler-and-reservoir means in said reservoir section including a sheet element of convolute form, means main taining said convolutions in predetermined spaced relation to define a continuous capillary ink storage space therebetween of spiral cross-sectional shape and extending longitudinally of said reservoir section, said convolutions being provided with spaced openings therethrough of predetermined size and arrangement providing communication between the portions of said space onopposite sides of said convolutions, the innermost convolution defining an air vent passage of greater diameter than the spacing between adjacent convolutions and extending longitudinally of said sheet element member, said innermost convolution having spaced openings extending therethrough providing communication between said air passage and said ink storage spaces, and means for venting said air passage to atmosphere.

9. A fountain pen comprising a body having a reservoir chamber and an opening extending from said reservoir chamber through the forward end of said body, a nib in said opening, a feed bar in said opening and havinga feed channel therein communicating with said reservoir chamber and in ink feeding relation to said nib, and a capillary filler-and-reservoir element in said reservoir chamber including a sheet of non-absorbent material spirally rolled upon itself to definea continuous spiral ink storage space of capillary width, the convolutions of said sheet having spaced projections of predetermined heights abutting adjacent convolutions for maintaining said convolutions in said predetermined, substantially uniformly spaced relation, said capillary filler-andreservoir element being disposed with one end abutting said feed bar to place said spiral space in ink feeding relation with said feed channel.

10. A fountain pen com-prising a body having a reservoir chamber and an opening extending from said reservoir chamber through the forward end of said body, a-nib in said opening, a feed bar in said opening and having a feed channel therein communicating with said reservoir chamber in ink feeding relation to said nib, a capillary filler-and-reservoir element in said reservoir chamber and including a sheet of material spirally rolled upon itself, with consecutive turns thereof spaced apart to define a continuous spiral ink storage space of capillary width, said sheet being of sufiiciently rigid material to maintain its rolled:- shape; and having spaced openings'of'p'redetermined sizes and arrangement extending through. adjacent convolutions thereof for connecting the portionsof said spiral space on opposite sides of said convolutions, said capillary filler and-reservoir element being disposed with one endabutting said feed bar to place said spiral space in ink feeding relation with said feed channel.

11. A, fountain pen comprising a body having a reservoir chamber and an opening extending fromsaid reservoir chamber through the forward end of ,said body, anib in said opening, a feed bar inisaid opening and having a feed channel therein, communicating with said reservoir chamber and in ink feeding relation to said nib, a capillary filler-and-reservoir element in said reservoir chamber including a sheet of material spirally rolled upon itself to define a continuous spiral space of capillary'width, the convolutions of said sheet having spaced projections abutting adjacent convolutions thereof for maintaining said convolutions in said spaced relation, and spaced openings extending through said convolutions for connecting the portions of said spiral space on opposite sides of said convolutions, said capillary filler-and-reservoir element being disposed with one end abutting said feed bar to place said spiral space in ink feeding relation with said feed channel.

12. A fountain pen comprising a body having a reservoir section'and a feed section, a writing element at the forward end of said body, ink feed means in said feed section and having a capillary ink feed passage connected to said writing element, a capillary filler-and-reservoir element in said reservoir section including a member of sheet material rolled upon itself, the convolutions of said member having projections thereon maintaining the convolutions in spaced relation to define a capillary ink storage space of spiral crosssection and openings through said convolutions providing communication between the portions of said ink storage space on opposite sides of said member, and resilient means abutting the rear end of said capillary filler-and-reservoir element for positioning said filler element in said reservoir section in abutment with said feed means to maintain said capillary space in ink feeding relation with the ink feed passage in said feed means.

13. A fountain pen comprising a body having a reservoir section and a feed section, a writing element at the forward end of said body, ink feed means in said feed section associated with said writing element, and having a capillary ink feed passage therein, a capillary filler-and-reservoir element in said reservoir section including a spirally wrapped member of perforated sheet material, means maintaining the convolutions of said member in spaced relation whereby the latter define a continuous spiral capillary ink storage space open at its forward end, with the convolutions of said space intercommunicating through the perforations in said sheet, and means for pcsitioning said filler-and-reservoir element in said reservoir section in abutment with said feed means to maintain said spiral capillary space in ink feeding relation with said feed means.

14. A fountain pen comprising a body having a reservoir section and a feed section, a writing element at the forward end of said body, ink feed means in said feed section associated with said writing element, and having a capillary ink feed passage therein open at its rear end, a capillary filler-andereservoir element in said reservoir section including a spirally rolled sheet, means maintaining the convolutions thereof in spaced relation whereby the latter define-a continuous spiral capillary ink storage spaceopcn at both ends, said sheet; having openings in said convolutions providing communications between portions of said; ink storage space on opposite sides of; said convolutions, a resilient'annular member abutting the rearwardend of said'filler element and; in axial alignmentv therewith for positioning said filler-and-reservoir element in, said reservoir section in abutment, with said feed means to maintain said spiral capillaryspace in ink feed? ing relation with said feed means, and a vent passage in. said body extending-g rearwardly from said reservoir section, said. annular member having a passage therein; connecting the rear ends of substantially all of the turns of said spiral space to said vent passage.

15. A capillary filler-and-resorvoir element for: a fountain pen comprising a sheet, of non-absorbent material spirally rolled upon itself and; defining between the convolutions thereof a continuous ink storage space of spiral cross-section and capillary width, and spaced projections on said sheet abutting adjacent convolutions for maintaining the latter in predetermined spaced relation, between approximately 0.004 and approximately 0.008".

16. A capillary filler-and-reservoir element for a fountain pen comprising a sheet of material spirally rolledupon itself, means maintaining the convolutions of said sheet in spaced relation whereby'there is defined between, said convolutions a continuous ink storage' space of spiral cross-section, and capillary width, saidsheet hav-- ing spaced openings extending through the con volutions thereof providing communication between the portions of said capillary space on opposite sides of said convolutions.

17. A capillary filler-and-reservoirelement for a-fountain pen comprising a sheet of material spirally rolled upon itself and defining betweenthe convolutions thereof a continuous spiral ink storage space of capillary width, said sheet havingspaced projections thereon abutting adjacent convolutions for maintaining the latter in spaced relation and spaced openings extending through said sheet providing communication between the portions of said capillary space on opposite sides ofsaid convolutions.

18. A capillary filler-and-reservoir element for a fountain pen comprising a sheet of material spirally rolled upon itself and defining between the convolutions thereof a continuous spiral ink storage space of capillary width, said sheet havingspaced projections thereon abutting adjacent convolutions for maintaining the latter in spaced relation and openings extending through at least certain of said projections providing communication between the portions of said capillary space on opposite sides of said convolutions.

19. A capillary filler-and-reservoirelement comprising a sheet of non-absorbent material spirally rolled upon itself and defining between the convolutions thereof a continuous ink storage space of spiral cross-section and capillary width, said sheet being formed at a marginal portion thereof adjacent an end of said filler-and-reservoir element with a slit defining a capillary-feed passage of greater capillarity than said storage space and connected in ink feeding relation to said spiral capillary space.

20. In a fountain pen having a pen body formed with a vented reservoir chamber, and a writing element at one end of said body, a capillary filler-and-reservoir element in said chamber comprising non-absorbent wall means defining a continuous, substantially unobstructed ink storage space of substantially uniform capillary Width and generally spiral cross-section extending longitudinally substantially throughout the length of said reservoir chamber, the convolutions of said space being interconnected at predetermined spaced points throughout their length and. breadth and open at both ends, and connected in feeding relation to said writing element.

21. A fountain pen comprising a writing element, and a capillary filler-and-reservoir element including a Wall-forming member of non-absorbent sheet material rolled upon itself, means spacing the convolutions of said sheet apart whereby said convolutions provide spaced, continuous wall surfaces defining therebetween a continuous capillary ink storage space of spiral cross-sectional shape, said member having spaced openings of predetermined sizes and arrangement extending through the convolutions thereof and providing communication between the portions of said storage space on opposite sides of said convolutions, said ink storage spaces being connected in ink feeding relation with said writing element.

22. A fountain pen comprising a writing ele-' ment, a capillary filler-and-reservoir element including a wall-forming member of sheet material rolled upon itself with the convolutions thereof REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 255,205 Stone Mar. 21, 1882 1,001,225 Sinnott Aug. 22, 1911 1,336,119 Andersen Apr. 6, 1920 1,472,576 Averill Oct. 30, 1923 2,114,118 Studer et al Apr. 12, 1938 2,462,929 Zodtner Mar. 1, 1949 FOREIGN PATENTS Number Country Date 515,113 France Mar. 24, 1921 703,046 Germany 1941 

